Extract fields with search commands

The rex command performs field extractions using named groups in Perl regular expressions.

The extract (or kv, for key/value) command explicitly extracts field and value pairs using default patterns.

The multikv command extracts field and value pairs on multiline, tabular-formatted events.

The spath command extracts field and value pairs on structured event data, such as XML and JSON.

The xmlkv and xpath commands extract field and value pairs on XML-formatted event data.

The kvform command extracts field and value pairs based on predefined form templates.

In Splunk Web, you can define field extractions on the Settings > Fields > Field Extractions page.

The following sections describe how to extract fields using regular expressions and commands. See About fields in the Knowledge Manager Manual.

Extract fields using regular expressions

The rex command performs field extractions using named groups in Perl regular expressions that you include in the search criteria. The rex command matches segments of your raw events with the regular expression and saves these matched values into a field.

In this example, values that occur after the strings From: and To: are saved into the from and to fields.

... | rex field=_raw "From: (?<from>.*) To: (?<to>.*)"

If a raw event contains From: Susan To: Bob, the search extracts the field name and value pairs: from=Susan and to=Bob.

For a primer on regular expression syntax and usage, see www.regular-expressions.info. The following are useful third-party tools for writing and testing regular expressions:

Extract fields from .conf files

The extract command forces field/value extraction on the result set. If you use the extract command without specifying any arguments, fields are extracted using field extraction stanzas that have been added to the props.conf file. You can also use the extract command to test field extractions that you add to the conf files.

Extract fields from events formatted as tables

Use the multikv command to force field and value extractions on multiline, tabular-formatted events. The multikv command creates a new event for each table row and derives field names from the table title.

Extract fields from events formatted in XML

The xmlkv command enables you to force field and value extractions on XML-formatted tags in event data, such as transactions from web pages.

Extract fields from XML and JSON documents

The spath command extracts information from structured data formats, such as XML and JSON, and store the extracted values in fields.

Extract fields from events based on form templates

The kvform command extracts field and value pairs from events based on form templates that are predefined and stored in $SPLUNK_HOME/etc/system/local/, or your own custom application directory in $SPLUNK_HOME/etc/apps/. For example, if form=sales_order, the search looks for a sales_order.form, and matches all processed events against that form to extract values.

If you have Splunk Cloud and want to use form templates for field extraction, file a Support ticket.

Enter your email address, and someone from the documentation team will respond to you:

Send me a copy of this feedback

Please provide your comments here. Ask a question or make a suggestion.

Feedback submitted, thanks!

You must be logged into splunk.com in order to post comments.
Log in now.

Please try to keep this discussion focused on the content covered in this documentation topic.
If you have a more general question about Splunk functionality or are experiencing a difficulty with Splunk,
consider posting a question to Splunkbase Answers.

0
out of 1000 Characters

Your Comment Has Been Posted Above

We use our own and third-party cookies to provide you with a great online experience. We also use these cookies to improve our products and services, support our marketing campaigns, and advertise to you on our website and other websites. Some cookies may continue to collect information after you have left our website.
Learn more (including how to update your settings) here »